Image forming apparatus

Abstract

An image forming apparatus includes a photosensitive member, a charging device, a developing device, a thickness detecting unit and a parameter setting unit. A photosensitive layer is formed on a surface of the photosensitive member. The charging device charges the photosensitive member. The developing device forms a toner image on the surface of the photosensitive member. The thickness detecting unit detects a thickness of the photosensitive layer on a basis of a value of a current supplied to the charging device. When the thickness detecting unit detects the thickness of the photosensitive layer, the parameter setting unit sets at least one of a charge parameter for the charging device and a development parameter to be different from that used in forming an image on a recording medium by transferring a toner image formed on the surface of the photosensitive member onto the recording medium.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention will be described in detail based on the following figures, wherein:

FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to exemplary embodiments of the invention;

FIG. 2 is a view illustrating specific examples of a processing operation of the image forming apparatus according to a first exemplary embodiment of the invention, FIG. 2A is a view illustrating a processing operation when detecting a thickness of a photosensitive layer, and FIG. 2B is view illustrating a processing operation when forming an image;

FIG. 3 is a view illustrating specific examples of a charge parameter, which the image forming apparatus according to the first exemplary embodiment sets, FIG. 3A is a view illustrating an example of a set value of an applied current and FIG. 3B is a view illustrating an example of a set value of an AC frequency;

FIG. 4 is a view illustrating specific examples of a processing operation of the image forming apparatus according to a second exemplary embodiment of the invention;

FIG. 5 is a view illustrating a specific example of a processing operation of an image forming apparatus according to still another exemplary embodiment of the invention; and

FIG. 6 is a view illustrating a specific example of a processing operation of an image forming apparatus according to further another exemplary embodiment of the invention.

Claims

1. An image forming apparatus comprising: a photosensitive member, a photosensitive layer formed on a surface of the photosensitive member;a charging device that charges the photosensitive member;a developing device that forms a toner image on the surface of the photosensitive member;a thickness detecting unit that detects a thickness of the photosensitive layer on a basis of a value of a current supplied to the charging device; anda parameter setting unit, wherein when the thickness detecting unit detects the thickness of the photosensitive layer, the parameter setting unit sets at least one of a charge parameter for the charging device and a development parameter for the developing device to be different from that used in forming an image on a recording medium by transferring a toner image formed on the surface of the photosensitive member onto the recording medium.

2. An image forming apparatus comprising: a photosensitive member, a photosensitive layer formed on a surface of the photosensitive member;a charging device that charges the photosensitive member;a developing device that forms a toner image on the surface of the photosensitive member;a thickness detecting unit that detects a thickness of the photosensitive layer on a basis of a value of a current supplied to the charging device; anda parameter setting unit, wherein when the thickness detecting unit detects the thickness of the photosensitive layer, the parameter setting unit sets at least one of a charge parameter for the charging device and a development parameter to be different from that used in forming an image on a recording medium by transferring a toner image formed on the surface of the photosensitive member onto the recording medium, wherein:the parameter setting unit sets a bias voltage applied to the developing device as the development parameter for the developing device, andwhen the thickness detecting unit detects the thickness of the photosensitive layer, the parameter setting unit sets the development parameter so as to provide a period in which a value of a bias voltage is larger than that used in forming the image on the recording medium.

3. The apparatus according to claim 2, wherein the parameter setting unit sets the bias voltage on a basis of potential of the surface of the photosensitive layer after the charging device charges the photosensitive member.

4. The apparatus according to claim 3, further comprising: a monitoring unit that monitors the potential of the surface of the photosensitive layer and notifies a monitored potential to the parameter setting unit.

5. The apparatus according to claim 1, wherein: the parameter setting unit sets a current, which the charging device applies when charging, as the charge parameter for the charging device, andwhen the thickness detecting unit detects the thickness of the photosensitive layer, the parameter setting unit sets a value of the applied current to be smaller than that used in forming the image on the recording medium and to be larger than a value of a current inflection point on a curve of an AC current value flowing through the charging device versus a potential of the surface of the photosensitive layer.

6. The apparatus according to claim 1, wherein: the parameter setting unit sets an AC frequency used when the charging device charges, as the charge parameter for the charging device, andwhen the thickness detecting unit detects the thickness of the photosensitive layer, the parameter setting unit sets a value of the AC frequency to be smaller than that used in forming the image on the recording medium.

7. The apparatus according to claim 5, further comprising: a sensor that monitors an apparatus use environment including at least one of temperature and humidity, wherein: the parameter setting unit changes the applied current used when the charging device charges, in accordance with at least one of the thickness of the photosensitive layer detected by the thickness detecting unit and a monitoring result by the sensor.

8. The apparatus according to claim 6, further comprising: a sensor that monitors an apparatus use environment including at least one of temperature and humidity, wherein: the parameter setting unit changes the AC frequency used when the charging device charges, in accordance with at least one of the thickness of the photosensitive layer detected by the thickness detecting unit and a monitoring result by the sensor.

9. An image forming apparatus comprising: a photosensitive member, a photosensitive layer formed on a surface of the photosensitive member;a charging device that charges the photosensitive member;an exposing device that exposes the surface of the photosensitive member, which has been charged by the charging device;a developing device that forms a toner image on the surface of the photosensitive member;a cleaning member that is in sliding friction with the surface of the photosensitive member to remove residue on the surface of the photosensitive member;a thickness detecting unit that detects a thickness of the photosensitive layer on a basis of a value of a current supplied to the charging device; anda friction reducing unit, when the thickness detecting unit is to detect the thickness of the photosensitive layer, the friction reducing unit reducing a coefficient of friction between the surface of the photosensitive member and the cleaning member.

10. The apparatus according to claim 9, wherein: the friction reducing unit causes the developing device to supply a toner to the surface of the photosensitive member and makes the toner on the surface of the photosensitive member function as a lubricant between the surface of the photosensitive member and the cleaning member, to reduce the coefficient of friction between the surface of the photosensitive member and the cleaning member.

11. The apparatus according to claim 10, wherein the friction reducing unit causes the developing device to supply the toner to the surface of the photosensitive member during a period in which the thickness detecting unit is detecting the thickness of the photosensitive layer.

12. The apparatus according to claim 10, wherein the friction reducing unit causes the developing device to supply the toner to the surface of the photosensitive member before the thickness detecting unit starts detecting the thickness of the photosensitive layer.

13. The apparatus according to claim 10, wherein the friction reducing unit causes the developing device to supply the toner of 0.01 mg/cm2 or more to the surface of the photosensitive member so that the toner on the surface of the photosensitive member functions as the lubricant.

14. The apparatus according to claim 10, wherein the friction reducing unit causes the developing device to supply a toner to the surface of the photosensitive member and makes the toner on the surface of the photosensitive member function as a lubricant between the surface of the photosensitive member and the cleaning member, to reduce the coefficient of friction between the surface of the photosensitive member and the cleaning member by at least 10% in comparison with the coefficient of friction therebetween in forming the image on the recording medium by transferring the toner image formed on the surface of the photosensitive member onto the recording medium.

15. The apparatus according to claim 10, wherein the friction reducing unit reduces an amount of charges provided to the photosensitive member by the charging device to be smaller than an amount of charges provided to the photosensitive member in an image forming operation of transferring the toner image formed on the surface of the photosensitive member onto a recording medium.

16. The apparatus according to claim 10, wherein the friction reducing unit raises a voltage applied to the developing device to be larger than that applied to the developing device in an image forming operation of transferring the toner image formed on the surface of the photosensitive member onto a recording medium.

17. The apparatus according to claim 10, wherein the friction reducing unit causes the exposing device to perform an exposing operation, to cause the developing device to supply the toner.

18. The apparatus according to claim 9, wherein the friction reducing unit reduces a contact pressure of the cleaning member against the surface of the photosensitive member to be smaller than that in an image forming operation of transferring the toner image formed on the surface of the photosensitive member onto a recording medium, to reduce the coefficient of friction between the surface of the photosensitive member and the cleaning member.

19. The image forming apparatus according to claim 1, further comprising: an operation controlling unit, when the thickness detecting unit is to detect the thickness of the photosensitive member, the operation controlling unit controlling an operation of the photosensitive member so as to operate at as high speed as possible.

20. The apparatus according to claim 19, wherein, when an image forming operation of transferring a toner image onto a recording medium is performed after a thickness detecting operation performed by the thickness detecting unit or when the thickness detecting operation is performed after the image forming operation, the operation controlling unit starts the image forming operation or the thickness detecting operation to be subsequently performed without performing a cycle down operation between the operations.